Layer-4 transparent secure transport protocol for end-to-end application protection
Techniques for providing layer 4 transparent secure transport for end-to-end application protection are described herein. According to one embodiment, a packet of a network transaction is received from a client over a first network, where the packet is destined to a server of a data center having a plurality of servers over a second network. The packet includes a payload encrypted without encrypting information needed for a layer 4 of OSI (open system interconnection) layers of network processes. The layer 4 process is performed on the packet without having to decrypting the payload to determine whether the packet is eligible to access the destined server over the second network based on the unencrypted layer 4 information. Other methods and apparatuses are also described.
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This application claims the benefit of U.S. Provisional Patent Application No. 60/966,649, filed Aug. 28, 2007, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTIONThe present invention relates generally to secure transport protocols. More particularly, this invention relates to layer-4 transparent secure transport protocols for end-to-end application protection.
BACKGROUNDThe ability to connect information technology infrastructure reliably, cost-effectively and securely is of high importance for today's global enterprises. To communicate with customers, clients, business partners, employees, etc., the Internet has proven to be more appropriate compared to private communication networks. However, communication via the Internet, which typically uses TCP/IP (Transmission Control Protocol/Internet Protocol), also increases the requirements for data security. Network firewalls are one of the many examples of solutions for network security.
Enterprise Web Application Services build an important foundation for such client, customer, and employee communication. A very common configuration for hosting such enterprise web Application Services is shown in
A client 1003 may connect via a Local Area Network (LAN) through the enterprise's intranet 1013. Another client 1004 may connect through a Wireless LAN (WLAN) to the intranet 1013. Yet another client 1005 may be located inside the enterprise's campus network 1015, which connects to the enterprise's intranet 1013. An enterprise may have zero or more campuses 1014 and 1015. Yet another client 1001 may connect through the Internet 1000, or a client 1002 may have a mobile connection to the Internet 1000. In any case to prevent illegitimate access to the enterprise's web Application Services, the “inside” of the enterprise's network, the intranet 1013, is protected by having a network perimeter 1010, which may comprise firewalls, associated network interconnect, and additional resources “within” the perimeter network configured so as to be broadly accessible to users on the “outside” of the enterprise.
Behind the perimeter 1010, access is granted to legitimate client requests only, while illegitimate access is rejected. The fundamentals in determining whether an access request is legitimate or not are based on the network reference model from the International Organization for Standardization (ISO). This ISO network reference model classifies Network Services into seven layers.
Traditional security products generally assume the existence of a trusted intranet—locations where enterprises control their own LANs, switches and routers—which can be organized into or placed within some type of security perimeter, to protect its resources from the un-trusted Internet. However, in today's business environment, enterprises no longer enjoy the same level of trust and control of their intranets, as enterprises increasingly rely on contractors, partners, consultants, vendors, and visitors on-site for daily operation. As a result, enterprises are exposing internal resources to this wide set of clients whose roles are also frequently changing. Thus, the network trust boundary, delineating inside and outside clients, is disappearing—a phenomenon referred to as “de-perimeterization”. In such an environment, protection of an enterprise's resources—such as its intellectual property, as well as mission-critical and operational systems—becomes of critical importance. Also, most security exploits easily traverse perimeter security, as enterprises typically let through email, web and any encrypted network traffic, such as Secure Sockets Layer (SSL), Simple Mail Transfer Protocol (SMTP) with Transport Layer Security (TLS), and authenticated Virtual Private Network (VPN) traffic, for example via IP Security (IPSec). Traditional perimeter security approaches, for example firewalls, intrusion detection systems and intrusion prevention systems have little or no benefit at the perimeter in providing access control functions to the resources. They have become more attack mitigation mechanisms than access control mechanisms. Enterprises are coming to terms with the fact that a hardened perimeter strategy is un-sustainable.
Traditional firewall or router access control lists cannot protect application resources from unauthorized access because network parameters such as Internet Protocol (IP) addresses and IP port numbers no longer deterministically identify resources, nor identify users, clients, or applications accessing these resources. Network firewall technology was invented when enterprises had a limited set of applications such as Telnet, File Transfer Protocol (FTP), and Email, and its primary functions were to limit access to specific applications from the outside and to limit access by systems within the enterprise to specific applications outside the firewall. Network layer parameters such as source, destination IP address and TCP or UDP port numbers were sufficient to identify the client and the operations the clients intended to perform on a particular resource. However, with the proliferation of mobile devices and tunneled applications, the network layer parameters are no longer useful to identify the client, the resource accessed, and the operation. Firewalls have evolved over the time, embracing functions such as deep packet inspection and intrusion detection/prevention, to handle application-level attacks, but the core access control function remains the same.
In effect, de-perimeterization demands that access control functions are positioned close to application resources and that a micro-perimeter is established in the heart of the data center by placing an identity-based policy enforcement point in front of any application resource. Enterprise business drivers for such an enforcement point are the need for rich and uniform protection of resources, business agility via attribute-based, policy-driven provisioning, and regulatory compliance. Traditional server-centric authorization solutions providing role-based authorization often require custom code development, extensive cross-vendor testing whenever there is a version change (of the underlying operating system, agent or application), and are costly and difficult to maintain because of their proprietary nature. Also, traditional server-based network appliances—primarily focused on low-bandwidth ISO Layer-4 to ISO Layer-7 perimeter services—are unsuitable for data center deployment, both in functional richness and in ISO Layer-7 performance.
SUMMARY OF THE DESCRIPTIONTechniques for providing layer 4 transparent secure transport for end-to-end application protection are described herein. According to one embodiment, a packet of a network transaction is received from a client over a first network, where the packet is destined to a server of a data center having a plurality of servers over a second network. The packet includes a payload encrypted without encrypting information needed for a layer 4 of OSI (open system interconnection) layers of network processes. The layer 4 process is performed on the packet without having to decrypting the payload to determine whether the packet is eligible to access the destined server over the second network based on the unencrypted layer 4 information.
Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements.
In the following description, numerous details are set forth to provide a more thorough explanation of embodiments of the present invention. It will be apparent, however, to one skilled in the art, that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present invention.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification do not necessarily all refer to the same embodiment.
One aspect of the invention provides a Transparent Secure Transport mechanism between client-to-server (or server-to-server) connections which will not break existing ISO Layer-4 networking. While the payload (i.e. the sensitive data) is encrypted for privacy and security, the original TCP and IP headers are kept unchanged. This results in a secure transport method which is transparent to existing ISO Layer-4 network services.
One aspect of the invention is a system and method for Transparent Secure Transport for End-to End Application Protection, comprising a method for secure transport in a network environment using data packets which protects the transported data by encrypting the payload of the data packets and which does not alter the ISO Layer-3 and ISO Layer-4 information of said data packets. The described Transparent Secure Transport (TST) may be dynamically installed and enabled in an endpoint by downloading the requisite TST agent software as needed into, for example, a client system, or, the requisite TST capabilities may be pre-installed in an endpoint.
Overview
The approach described herein applies combinations of parallel, multi-processor computing technology with lossless, low-latency, high-bandwidth network fabric technology (also known as Lossless Data Transport Fabric, or LDTF) to form novel methods and systems for high performance, high-reliability, high availability, and secure network applications. The various embodiments of the inventions described herein enable the implementation of highly reliable, highly scalable solutions for enterprise networking such as, for example, the APS 2000 from
Multiple network Services are efficiently provided by terminating transport protocols centrally. As can be seen, any transport protocol can be terminated centrally, each PDU's payload can be collected and converted into a data stream and, vice versa, a data stream can be converted into PDUs for any transport protocol and be transported via the given transport protocol. A simple concatenation of the PDU payload into a byte-stream is not sufficient. Key to the conversion is that state information must be maintained about the meta-data of each connection. Such meta-data includes the session information, for example via a unique connection identification number, the transaction information, as well as the information regarding segments and packets. Finite state machines can be used to track the meta-data.
Transport protocols are protocols which are used to transport information via networks. These include, obviously, the ISO Layer-3 protocols such as IPv4, IPv6, IPSec, the ISO Layer-4 protocols such as TCP, UDP, SCTP, the various ISO Layer-5 protocols such as FTP, HTTP, IMAP, SMTP, GTP, L2TP, PPTP, SOAP, SDP, RTSP, RTP, RTCP, RPC, SSH, TLS, DTLS, SSL, IPSec, and VPN protocols. However, other protocols and approaches are contemplated within the scope of the inventions, which serve as transport mechanisms for transmitting information and application data and can also be terminated in a centralized fashion by a protocol proxy and the corresponding PDUs can be transformed into a data stream for application layer processing. Examples of such are, CSIv2, CORBA, IIOP, DCOM and other Object Request Brokers (ORB), MPEG-TS or RTP as a transport for multi-media information, RTSP or SIP as another transport for multi-media information, peer-to-peer transport mechanisms, transport mechanisms based on J2EE such as Java RMI, streaming media protocols such as VoIP, IPTV, etc.
For the sake of simplicity we will use the term Centralized Transport Protocol Termination throughout the rest of the description, however, this is for exemplary purposes only and is not intended to be limiting. Centralized Transport Protocol Termination can be performed by dedicated processing units, and different ISO Layer-7 services can be performed in other dedicated processing units. The use of a lossless low-latency high-bandwidth fabric for inter-process communication between such dedicated processing units makes it possible to simultaneously support Centralized Transport Protocol Termination for multiple services. For example, TCP can be terminated once, transformed into a data stream and this data stream is transported from one dedicated processing unit to another using the lossless low-latency high-bandwidth fabric. The low-latency nature of the fabric helps to reduce the overall latency in client-to-server transactions.
In one embodiment, the Application Protection System (APS) 2000 is a network appliance that can act as a proxy between the client 2001 and the application server 2005, and can determine whether a client 2001 shall be granted access to certain applications 2005. In one example, the client 2001 is one or more of the clients 1001, 1002, 1003, 1004, or 1005 of
The APS 2000 may use a Triangulated Authorization method which, for example, is based on multiple aspects of a client (such as the client 2001), the requested application (such as application 2005) and certain network characteristics: Who—a client (a user or a machine) and its associated attributes such as department, role, project association, seniority, citizenship, etc; Where—network and environment attributes such as access methods (wire-line/wireless/VPN), location (e.g., USA, Switzerland, China) and time; What—on-the-wire session attributes, including protocol and content/resource attributes. The outcome of this Triangulated Authorization method can be used to determine whether access to an application is granted or rejected. Optionally, a Single-Sign-On (SSO) server such as server 2004 may be involved that allows the client 2001 to obtain authorization for accessing multiple applications at once.
One embodiment of the invention acts as a proxy between one or more clients and one or more application servers to control the access of the one or more clients to the one or more applications. This is described, for example, in
Transparent Secure Transport Based on Policies
For end-to-end protection, one embodiment of the invention can provide encrypted Transparent Secure Transport for client sessions without breaking existing ISO Layer-2 to ISO Layer-4 services. Because the primary target of this function is to provide data privacy for internal communication, it is important to keep visibility to network headers so that network operators can continue to use traditional traffic monitoring and protocol analysis tools. Also this approach allows the Transparent Secure Transport function to co-exist with existing network layer services such as access control lists (ACL) and Quality of Service (QoS). The Transparent Secure Transport functionality allows creation of resource enclaves with different levels of security. For example, all sessions destined to high-security enclaves would always be encrypted while sessions destined to medium-security enclaves would be cryptographically authenticated only. Like the Triangulated Authorization service support, the Transparent Secure Transport service of our approach is non-invasive to application resources.
Different security zones can be created with different levels of security based on policies. For example, encryption and integrity checks may be used for very sensitive data. In this case the payload in the each packet is encrypted and an integrity code (for example, a Message Authentication Code) is added to make sure there is no tampering with the encrypted data in between. For less sensitive data, only integrity codes may be added to each packet to make sure no one tampers with the data in between; however, the data itself is not encrypted.
The Transparent Secure Transport of this approach, for example, Transparent Secure Transport 2011 or Transparent Secure Transport 2012, are transparent to existing ISO Layer-4 services, unlike other approaches known in the art such as IPSec or SSL-based VPN. For example, a packet, which is transported via IPSec's Transport Mode, will have its TCP header encrypted. A packet includes an Original IP header, a TCP header and data, which is transported via IPSec's Tunneling Mode will not only have the TCP header but also have the Original IP header encrypted. In both cases this prevents existing ISO Layer-4 services from analyzing such network traffic because the original IP header and the TCP header are not visible anymore during such secure transport.
Transparent Secure Transport for End-to-End Application Protection
In one embodiment of the invention described herein, the ANA shown in
This drawback of encrypting the original IP information is solved by one embodiment of the invention described herein. According to one embodiment of the invention, the original data packet 5030 can be sent by transporting it within the packet 5040. The original destination IP address 5031 and the original destination TCP port number 5032 are used unencrypted such that ISO Layer-4 network analysis can seamlessly be applied. Therefore the transport mechanism of this approach is transparent to existing networking. And because the original payload 5033 gets encrypted into the encrypted payload 5042 plus an encryption header, for example SSL header 5041, the transport is also secure. In one embodiment of the invention, SSL is used for encrypting the payload. In another embodiment of the invention, DTLS is used for encrypting the payload.
In another embodiment of the invention, the Transparent Secure Transport can use a different Transparent Secure Transport depending on a particular security zone configured in a policy. This is described in conjunction with
Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Embodiments of the present invention also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), erasable programmable ROMs (EPROMs), electrically erasable programmable ROMs (EEPROMs), magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method operations. The required structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of embodiments of the invention as described herein.
A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes read only memory (“ROM”); random access memory (“RAM”); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); etc.
In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
Claims
1. A method comprising:
- at a service module of a network device, receiving a packet of a network transaction from a client device over a first network;
- obtaining policy information from a gateway device via a secure control channel;
- analyzing the policy information to determine a security zone classification associated with the packet;
- when the security zone classification requires high security for the packet: encrypting a portion of the packet with an encryption header that contains payload information while maintaining an unencrypted portion of the packet comprising destination address information of the packet such that layer 4 processing can be applied to the packet;
- adding to the packet an integrity code that is associated with the payload information to authenticate the packet;
- performing layer 2 to layer 4 (layer 2-4) processes on the unencrypted portion of the packet without having to decrypt the encrypted portion of the packet such that the packet maintains a transparent secure transport function; and
- evaluating an authorization of the packet to determine whether the packet is eligible to access a server of a data center over a second network based on network characteristics of the packet obtained from the layer 2-4 processes.
2. The method of claim 1, wherein performing the layer 2-4 processes comprises performing a layer 4 access control process for transparent secure transport of the packet to determine whether the packet is eligible to access the server over the second network based on unencrypted layer 4 information.
3. The method of claim 1, wherein evaluating the authorization comprises determining whether the packet is eligible to access the server when the second network is an internal network of an organization associated with the data center.
4. The method of claim 1, wherein receiving comprises receiving the packet such that at least an Internet Protocol (IP) header containing a destination IP address and a Transport Control Protocol (TCP) header containing a destination TCP port of the packet is not encrypted and remains unchanged while the payload information of the packet is encrypted.
5. The method of claim 1, wherein receiving comprises receiving the packet that is encrypted by a security agent of the client device, wherein the security agent encrypts at least the payload information of the packet without encrypting information in the packet needed for the layer 2-4 process.
6. The method of claim 5, further comprising:
- at the service module, receiving information of the security agent over the first network in response to a request from the client device to initiate a network connection; and
- transmitting a plurality of security parameters to the client device over the secure control channel for a policy associated with the client device.
7. The method of claim 6, further comprising:
- establishing a secure control channel with the security agent over the first network in response to a request received from the security agent; and
- negotiating the security parameters with the agent over the secure control channel.
8. The method of claim 7, further comprising:
- trapping network traffic if the network traffic requires a security service based on the policy associated with the client device;
- receiving the packet with the encrypted payload information of the network traffic that has been encrypted using the security parameters if the network traffic requires a security service; and
- performing layer 3 to layer 4 (layer 3-4) processes on unencrypted information of the packet.
9. The method of claim 1, wherein receiving comprises receiving the packet at the service module of the network device that is a security gateway between the client device and a plurality of servers of the data center.
10. The method of claim 8, wherein receiving comprises receiving the packet over the first network that is an external network such that the network traffic is encapsulated within a secure tunnel over the first network which is terminated at the network element to recover packets with the encrypted payload and unencrypted information from the layer 3 to layer 4 (layer 3-4) processes.
11. The method of claim 1, and further comprising obtaining network characteristics of the packet from the layer 2-4 processing of the packet, wherein evaluating the authorization of the packet comprises determining comprises determining whether the packet is eligible to access the server based on the network characteristics that comprise one or more of client device attributes, network environment attributes and protocol and resource attributes.
12. A non-transitory machine-readable storage device storing instructions that, when executed by a machine, causes the machine to:
- receive at a service module of a network device a packet of a network transaction from a client device over a first network;
- obtain policy information from a gateway device via a secure control channel;
- analyze the policy information to determine a security zone classification associated with the packet;
- when the security zone classification requires high security for the packet: encrypt a portion of the packet with an encryption header that contains payload information while maintaining an unencrypted portion of the packet comprising destination address information of the packet such that layer 4 processing can be applied to the packet;
- add to the packet an integrity code associated with the payload information to authenticate the packet;
- perform layer 2-4 processes on the unencrypted portion of the packet without having to decrypt the encrypted portion of the packet such that the packet maintains a transparent secure transport function; and
- evaluate an authorization of the packet to determine whether the packet is eligible to access a server of a data center over a second network based on network characteristics of the packet obtained from the layer 2-4 processes.
13. The non-transitory machine-readable storage device of claim 12, wherein the instructions that cause the machine to perform the layer 2-4 processes comprise instructions that cause the machine to perform a layer 4 access control process for transparent secure transport of the packet to determine whether the packet is eligible to access the server over the second network based on the unencrypted layer 4 information.
14. The non-transitory machine-readable storage device of claim 12, wherein the instructions that cause the machine to evaluate the authorization of the packet comprise instructions that cause the machine to determine whether the packet is eligible to access the server when the second network is an internal network of an organization associated with the data center.
15. The non-transitory machine-readable storage device of claim 12, wherein the instructions that cause the machine to receive the packet comprise instructions that cause the machine to receive the packet such that at least an Internet Protocol (IP) header containing a destination IP address and a Transport Control Protocol (TCP) header containing a destination TCP port of the packet is not encrypted and remains unchanged while the payload information of the packet is encrypted.
16. The non-transitory machine-readable storage device of claim 12, wherein the instructions that cause the machine to receive the packet comprise instructions that cause the machine to receive the packet that is encrypted by a security agent of the client device, wherein the security agent encrypts at least the payload information of the packet without encrypting information in the packet needed for the layer 2-4 process.
17. The non-transitory machine-readable storage device of claim 16 further comprising instructions that cause the machine to: receive information of the security agent over the first network in response to a request from the client device to initiate a network connection; and transmit a plurality of security parameters to the client device over the secure control channel for a policy associated with the client device.
18. The non-transitory machine-readable storage device of claim 17 further comprising instructions that cause the machine to: establish a secure control channel with the security agent over the first network in response to a request received from the security agent; and negotiate the security parameters with the agent over the secure control channel.
19. The non-transitory machine-readable storage device of claim 18 further comprising instructions that cause the machine to: trap network traffic if the network traffic requires a security service based on the policy associated with the client device; receive the packet with the encrypted payload information of the network traffic that has been encrypted using the security parameters if the network traffic requires a security service; and perform layer 3 to layer 4 (layer 3-4) processes on unencrypted information of the network traffic.
20. The non-transitory machine-readable storage device of claim 19, wherein the instructions that cause the machine to receive the packet comprise instructions that cause the machine to receive the packet over the first network that is an external network such that the network traffic is encapsulated within a secure tunnel over the first network which is terminated at the network element to recover packets with an encrypted payload and unencrypted information from the layer 3 to layer 4 (layer 3-4) processes.
21. The non-transitory machine-readable storage device of claim 12, wherein the instructions that cause the machine to receive the packet comprise instructions that cause the machine to receive the packet at the service module of the network device that is a security gateway between the client device and a plurality of servers of the data center.
22. The non-transitory machine-readable storage device of claim 12, and further comprising instructions that caused the processor to obtain network characteristics of the packet from the layer 2-4 processing of the packet, and wherein the instructions that cause the processor to evaluate the authorization of the packet comprise instructions that cause the processor to determine whether the packet is eligible to access the server based on the network characteristics that comprise one or more of client device attributes, network environment attributes and protocol and resource attributes.
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Type: Grant
Filed: Apr 11, 2008
Date of Patent: Oct 23, 2012
Patent Publication Number: 20090059957
Assignee: Cisco Technologies, Inc. (San Jose, CA)
Inventors: Nagaraj Bagepalli (San Jose, CA), Prashant Gandhi (San Jose, CA), Abhijit Patra (San Jose, CA), Kirti Prabhu (San Jose, CA), Anant Thakar (Cupertino, CA)
Primary Examiner: Anh-Vu Ly
Assistant Examiner: Gbemileke Onamuti
Application Number: 12/101,862
International Classification: H04J 3/16 (20060101);